From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Comparison table of present and revised ignition timing settings for the Phantom engine.
| Identifier | ExFiles\Box 65\1\ scan0222 | |
| Date | 27th September 1928 | |
| X7685 27.9.28. PHANTOM IGNITION TIMING. Present. R1/L19.9.28. Battery hand range. 30° 30° Magneto hand range. 8° 15° Auto range. 28° to 30° 25° Full battery retard. 10° A.T.C. 10° Full magneto retard. 12° B.T.C. 5° Full battery advance. } 48° to 50° B.T.C. 45° Timing angles Full magneto advance. } reckoned on engine. Battery hand advanced, 20° B.T.C. 20° auto retarded. Magneto hand advanced, 20° B.T.C. 20° auto retarded. Battery auto advanced, 18° to 20° B.T.C. 15° hand retarded. Magneto auto advanced, 40° to 42° B.T.C. 30° hand retarded. EFC. | ||